Fluid pressure operated gear shifting device



May 11, 1937. D, 2,079,654

FLUID PRESSURE OPERATED GEAR SHIFTING DEVICE Filed MaICh 25. 1955 551. EC 70/? V1 V5 MECl/A/V/SM 7 3 TTORNEYS.

atente y 1937 FLUID PRESSURE OPERATED GEAR SHXFTING DEVICE Douglas F. Linsley, Old Greenwich, Conn, as-

signor to Vaco Products, Inc., a corporation of Delaware Application March 25,

8 Claims.

The present invention relates to automotive vehicles and more particularly to a novel and improvedfluid pressureoperated gear shifter capable of being operated under abnormal conditions.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts, construction, arrangements, combinations and improvements herein shown and described.

The accompanying drawing, referred to herein and constituting a part hereof, illustrates one embodiment of the invention, and together with the description, serve to explain the principles of the invention.

Of the drawing:

Figure 1 is a diagrammatic plan view showing an illustrative embodiment of the present invention and the interconnection of its various parts;

and

Figure 2 is a cross section of the clutch-operating cylinder shown in Figure 1.

The present invention has for its object the provision of a novel and improved fluid pressure operated gear shifting mechanism for use in connection with the transmissionin an automotive vehicle.

A further object of the invention is the provision of a vacuum-operated gear shifter and automatic clutch with which the gears can be shifted by actuation of the clutch mechanism upon failure of the vacuum-producing means. Still another object of the invention is the provision of a clutch-operating vacuum cylinder which may also serve as a vacuum pump.

Referring now in detail to the illustrative embodiment of the invention as shown in the accompanying drawing, the automotive vehicle is provided with an internal combustion engine It! connected through clutch. II to a conventional selective gear transmission [2 which serves to drive a propeller shaft l3 at different speeds relative to engine speed. A pedal I4 is provided for disengaging the clutch H which is normally held in engaged position by spring [5. The speed of the engine is controlled by means of a throttle valve IS in the intake l1, and throttle valve i6 is moved by means of accelerator pedal i8 or other suitable control means. Accelerator I8 is pivotally mounted and connected to the throttle valve 116 by means of link l9, pivoted bell 55 crank 20 and valve slide 2! of the clutch control 1935, Serial No. 12,961

valve 22, and is normally held in closed throttle or idling position by means of spring 23.

Vacuum-operated power means are provided for disengaging the clutch II when the throttle is in closed or idling position, and a vacuum cylinder 30 is provided with a piston 3| connected to the clutch pedal M, or other clutchoperating means, by means of piston rod 32 and link 33. At one end, cylinder 30 is connected with the intake manifold H at a point between the throttle valve l6 and the engine cylinders by means of vacuum lines 34, 35 and 36. The clutchcontrolling valve 22 comprises a slide 2| having a single valve opening 40 therethrough which serves to connect vacuum line 34 alternatively with vacuum line 35 or bleeder port 4|, depending upon the position of the accelerator pedal IB and throttle valve l6.

With the throttle in idling position, the slide 2! is positioned as shown in Figure 1, so that vacuum is applied to the end of cylinder 30 to disengage the clutch and hold it in disengaged relationuntil the accelerator pedal I8 is depressed. Depression of the pedal I8 causes the throttle IE to be opened, accelerating the engine in, and connecting vacuum line 34 with bleeder port 4|, instead of vacuum line 35, thereby admitting atmospheric air to the cylinder 30 and allowing spring l5 to engage the clutch I I.

The vacuum-operated gear shifting means may be of any desired construction and, as shown in Figure 1, comprises a pair of double-ended cylinders and 46 for selectively shifting the gears of the selective, sliding gear transmission l2 into the desired meshing relation to produce the desired driving ratio between the engine l0 and the propeller shaft l3.

Shifting cylinder 45 serves to shift the transmission into first or reverse speed, while cylinder 46 serves to shift the transmission into second, or third speed, and each of the cylinders 45 and 46 is provided with a vacuum line for returning its piston to neutral position. Cylinders 45 and 46 are connected with vacuum line 36 by means of the reverse vacuum line 50, neutral line 5|, first speed line 52, second speed line 53, neutral line 54 and third speed line 55.

The selection and bleeding of these several lines, as is required for the selective shifting of the gears to different speeds, is controlled by means of a selector valve 55, which in the illustrative embodiment is manually controlled.

Selector valve mechanism 55 is connected with the main vacuum line 36 by means of vacuum line 41 and through valve 60. Valve 60 comprises a small, narrow, cylinder connected at one end to vacuum line 36 by means of line ti, and slidably mounted within the cylinder is a piston valve slide 62 urged in one direction by a light compression spring 63, and moved against the compression of this spring by means of the vacuum applied to line 6!. v Valve slide 62 is'provided with a relatively deep groove 6% intermediate its ends and is also formed with an axial groove 65 extending for a considerable distance along its length to connect line M with port 66 when the engine is operating. When no vacuum is applied to the end of slide 62 through line 6!, the slide 62 is in the position shown in Figure 1. In that position, valve 60 connects line Ma with vacuum line Mi, while application of vacuum to the end of slide valve 62 through line H causes the slide to move against the compression of spring 63 to connect line Mb with vacuum line 6? which is a branch of the main vacuum line 36.

Under normal conditions and with the engine running, vacuum is available for the cylinders 65 and 46 through line 36, line 6'7, groove 66, lines 41 and Mb and the selector valve mechanism 55, but with the engine stopped, or in case a break occurs in the main vacuum line 36, the passageway between lines Mb and E7 is closed by the end of the slide 62.

Means are provided for creating a vacuum independently of the operation of the engine it and whenever the engine-produced vacuum is not available. As embodied, clutch-operating cylinder 30 is closed at both ends, and as previously described, the forward portion of this cylinder is adapted to be exhausted through vacuum line 36. At its other end, the cylinder is provided with opposed check valves i0 and ii, valve i0 permitting the air on the rear side of piston 3! to escape to atmosphere through vent 12 while valve H permits admission of air to the rear side of the piston 35 from line M as the piston is reciprocated. By opening the throttle it slightly, the forward side of piston 35 is in free communication with atmosphere through line 3 6 and port M.

Thus, when it is necessary to crank the car by hand, the throttle i6 is opened slightly, the selector valve is set for neutral position and the clutch pedal is actuated several times, returning the pistons in cylinders 35 and 6B and their associated gears to neutral. The car may then be cranked as the gears are in neutral and when the engine starts, the vacuum sucks piston valve slide 62 to the left, connecting line 68 to atmosphere through bleeder port 66.

In case there is a leakage of air into the main line 36, the operation is the same except that the operator may shift to any desired gear speed by the proper setting of the selector valve 55,

and similarly the gears may be shifted whenever desired without starting the engine.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.

What I claim is:-

1. In a vacuum operated gear shifter system,

the combination of an internal combustion engine, a vacuum operated clutch operated by said engine, a shiftable gear transmission, a vacuum aoracea operated gear shifter therefor, auxiliary means for operating said clutch and means for creating vacuum by operation of said auxiliary means and for applying the vacuum to the vacuum operated gear shifter.

2. In a vacuum operated gear shifting system the combination of an internal combustion engine, a vacuum operated clutch, a shiftable gear transmission, vacuum operated gear shifting means therefor normally operated by the running engine, an auxiliary source of vacuum and means for automatically connecting said gear shifter with said auxiliary source when the engine vacuum is not available to the gear shifter, said aux- -iiiary source of vacuum being actuated by operation of the clutch pedal.

3. In a vacuum operated gear shifter system the combination of an internal combustion engine, a shiftable gear transmission, vacuum operated gear shifting means operated by the intake manifold suction of the engine, an auxiliary source of vacuum, means for alternatively connecting the gear shifting means with the engine or-auxiliary source of vacuum, and means for controlling the connecting means by the running of the engine.

4. In a vacuum operated gear shifter system the combination of an internal combustion engine, a shiftable gear transmission, vacuum operated gear shifting means operated by the intake manifold suction of the engine, an auxiliary source of vacuum and means for alternatively connecting the gear shifting means with the engine or auxiliary source of vacuum.

5. In a vacuum operated gear shifter system the combination of an internal combustion engine, a shiftable gear transmission, vacuum operated gear shifting means operated by the intake manifold suction of the engine, an auxiliary source of vacuum, means for alternatively connecting the gear shifting means with the engine or auxiliary source of vacuum and means for controlling the connecting means by the availability of the vacuum to the gear shifter.

6. In a vacuum operated gear shifter system the combination of an internal combustion engine, a shiftable gear transmission, vacuum operated gear shifting means operated by the intake'manifold suction of the engine, an auxiliary source of vacuum and means for alternatively connecting the gear shifting means with the engine or auxiliary source of vacuum, said connecting means including a valve operated by vacuum from the engine.

7. In an automotive vehicle, the combination of an internal combustion engine, a vacuum op-.

of a vacuum operated motor comprising a cylind'er and piston, normally operated by the suction of an internal combustion engine, a spring, an-

element operated. by said cylinder against said spring, pedal means for operating said element and means for creating vacuum by the operation of said pedal means, said means comprising the piston and check valves within said vacuum cylinder.

. DOUGLAS F. LINSLEY. 

